Ares, who is incognito as a human, is on the side of Wonder Woman with his true form being "menacing af," according to WWThrowaway12233 and describes his look and actions.
"He floats, has armor, and a helmet that looks like a Greek Athenian battle helmet, and he can control lightning with his hands."
"Though the CGI isn't completely done, he looks like he could eat Doomsday for breakfast. His armour is very, very dark grey with a blood stained golden fleece on his right arm suspended by a belt with some sort of tiny horns. He has a shield which is small and expands into a rather large bladed shield. He has the God-Killer sword as his main weapon."
During the pre-screening, she loses the God-Killer sword to Ares. She later acquires another sword which is probably the one Batman v. Superman audiences had seen when she had taken on Doomsday.
Comparisons were even made to the toy line pictures that had leaked which described the Ares helmet consisting of animal skull and fur. As it turns out, that was about a concept art sketch. Redditor WWThrowaway12233 was pretty sure he remembered seeing Ares wearing a Greek helmet with a horizontal slot for the eyes and a slot going down the middle from the horizontal.
However, the AraenusWarlord movie pre-screener described it as such:
"Ares has a large blood stained Ram Skull Helmet which looks like that of the bad guy from HighLander."
"Trevor steals a book which has formulas and spells kinda stuff to create a gas capable of controlling minds and drive people into war against each other (like Kingsman: The Secret Service). One of its components is the gas created by Doctor Poison (the weird masked lady). Ares' plan is to create a war that would end half of humanity and regain his lost strength (Ares is powered by wars) and destroy Themiscyra and the Gods whom he despise. - The movie is great and I'd give it a 9/10. It lost its 1 point due to under usage of Danny Huston and Connie Nelson."
Another Redditor, aemon123, who interviewed someone in a question/answer session with a pre-screener, was also given a 9 out of 10 rating.